Conventionally, a gas circuit breaker including a movable contact and a fixed contact provided in a tank filled with an insulating gas has been used as disclosed in Patent Literature 1. In such a gas circuit breaker, as the movable contact comes into contact with the fixed contact, an electric current is supplied to a current supply target, and as the movable contact separates from the fixed contact, the electric current is cut off. The movable contact includes a nozzle that ejects the insulating gas in the tank toward the fixed contact when the movable contact separates from the fixed contact. The arc generated between the movable contact and the fixed contact is extinguished by the insulating gas ejected toward the fixed contact.